The man damaged the plane's inner plastic window during the flight. Yonhap

A Korean-American man is being investigated in Korea for "unruly behavior" on a flight from Los Angeles to Incheon, police said Thursday.According to police and Korean Air, the suspect, 31, caused a disturbance, damaged a window, cursed flight attendants and injured himself.

Other passengers were terrified when he broke the inner plastic window pane with his tablet computer as the plane was landing at Incheon International Airport early Wednesday.

The man now faces charges of violating Korea's Aviation Security Act and may have to spend much time (up to 10 years) in prison.

Other passengers and flight attendants said he looked mentally unstable from the beginning. For that reason, the flight crew had refused to serve him alcohol.